This invention relates to the field of faceted search. In particular, the invention relates to faceted search with relationships between categories.
A category is an aspect of indexed documents which can be used to classify the documents. For example, in a collection of books at an online bookstore, categories of a book can be its price, author, publication date, binding type, and so on.
In faceted search, in addition to the standard set of search results, facet results are also provided, which are lists of subcategories for certain categories. For example, for the price facet, a list of relevant price ranges is provided; for the author facet, a list of relevant authors is provided; and so on. In most user interfaces, when users click one of these subcategories, the search is narrowed, or drilled down, and a new search limited to this subcategory (e.g., to a specific price range or author) is performed.
One of the weaknesses of current faceted search systems is an inability to capture more complex data. For example, if different books in a bookstore have different bindings and prices, currently, modeling the store inventory in faceted search will result in different facets about every binding and price. However, not all books are available in all bindings and prices, and there is no way to capture complex facts such as “There are 10 copies from book X in paperback and price Y”. When a buyer wants to buy a copy of book X, the faceted navigation would offer facets about all available bindings and prices for that book. However, when selecting a certain binding, the price facet would not reflect the prices available for all bindings, rather the prices available for the binding selected. This does not provide the user with the requested information.